Currently available satellite based imaging sensors provide images of an entire hemisphere of the Earth, but these images are delayed by minutes, or even tens of minutes. Current satellites produce images of an entire hemisphere at moderate to low resolution, specifically, of five hundred meters to four kilometers per pixel. In some cases, conventional satellites provide images of small regions at high resolution delayed by tens of minutes, or even days. Over the last forty-five years, since the first weather monitoring satellite was placed in geostationary orbit (GSO), various satellite systems have been used to monitor features in the Earth and in the Earth's atmosphere.
Current commercial satellites are unable to produce Real-time images of a full hemisphere of the Earth due to the limitations imposed by their conventional design.
FIG. 1 offers a schematic view of the prior art, which includes a scanning mirror SM on a satellite in orbit. The scanning mirror SM collects light L from the Earth's surface ES, and directs it to imaging optics IO. The output from the imaging optics IO illuminates a conventional focal plane FP, which produces an electronic signal that is used to form an image.
FIG. 2 reveals another schematic view of the prior art. Conventional satellites may scan the observable Earth disk ED. Many scans SC1, SC2, SC3 through SCN, are generated in a sequential South to North fashion to produce an image of a full hemisphere. Non spinning satellites scans must include a scan retrace SR.
Conventional satellite imaging systems use scanning sensors, and produce images according to the method shown in FIG. 2.
The fastest satellite imaging system is the U.S. GOES-R weather satellite, and is planned for operation in 2017. The GOES-R uses a scanning sensor, and requires a minimum of five minutes to generate the scans that are then utilized to produce a full hemisphere image scanning sensors
The GOES-R full hemisphere image is downlinked and transferred into a data processing center at NASA's Goddard Space Center, where it is processed for several minutes. The processed image is then sent back up to the GOES-R satellite, which relays the image to users within the observable hemisphere (predominantly North and South America). This entire process takes about ten minutes.
A satellite which would be able to produce an image of a full hemisphere of the Earth would provide “persistent” imaging. These images would be extremely useful, especially in the fields of weather monitoring forecasting.
No conventional commercial satellite currently provides persistent imaging, defined as once every thirty seconds or more often, of an entire observable hemisphere. No current satellite provides high resolution of one hundred meters per pixel resolution in real-time.
The development of a system that enables remote access using mobile devices over trusted and secure links to these networks would be a major technological advance, and would satisfy long-felt needs in the satellite and telecommunications industries.